Coil winding apparatus



Nov. 27, 1962 G. B. AMEY COIL WINDING APPARATUS Filed Dee.A 15, 1958 2 Sheets-Sheet 1 o .P n M wv MQ vv INVENTGR. GEORGE B. AMEY NOV. 27, 1962 G. B. AMEY 3,065,772

COIL WINDING APPARATUS Filed Dec. l5, 1958 2 Sheets-Sheet 2 'f--- IIo voLTsV ACH P EI TIM fb DEI. 90 I\\ DEVICE '\I00 l 5 98 76 64 i "`f`` j 90b MJ CoNTRoLLED 1 92 VIIIRE [F |G 5 BYzQgUNTER 44a AUTOMATIC COUNTER -`-7\ RESET D INVENTOR. 94 ELEC RIC GEORGE B.AMEY vALvE I-'oR I GUN 7a BY l I :DRIVE MoToR oN/oFF /%M, W

ATTORNEY asesinas Patented Nov. 27, i962 tice 3,065,772 (29H. WENDHNG APPARATUS George B. Antey, Wiiiiamsport, Pa., assigner, by mesne assignments, to Sylvania Electric Products Inc., Wilmingtcn, Del., a corporation oir' Delaware Fiied Dec. 15, 1958, Ser. No. '730,612 13 Claims. (Cl 14d-92.2)

This inventionirelates to coil-winding machines, and is more particularly concerned with a machine for automaticaly winding coils of the formless type; i.e., coils lacking a center support or coil form.

A general object of the invention is to provide an improved method and machine for forming coils.

A more specific object of the invention is to provide a machine capable of winding coils of the formless type which are completely tinished when removed from the machine.

Another object of the invention is to provide a machine for automatically winding coils having -substantially uniform electrical characteristics from coil to coil.

Another object of the invention is to provide a coilwindin-g machine having means for causing adherence of adjacent turns of the coil, and including means to cut the leads of the coil to the proper length, so as to eliminate the need for secondary operations on the coil.

Briefly, the machine in accordance with the invention comprises a driven mandrel on which the coil is Wound, a wire guide for laying the wire down in a pattern along a portion of the leng-th lof the mandrel, and a control circuit including a preset counter for controlling the number of turns wound on the coil. While the coil is being wound, it is sprayed with a material which causesv adjacent turns to adhere to each other, whereby the coil is a self-supporting, secure unit upon completion. VWhen the coil has been wound with the prescribed number of turns, i-t is pushed to a new position on the mandrel, but not removed therefrom, preparatory to winding the next coil. The lfinish lead of the completed coil extending along the mandrel from the completed coil to the wire guide allows the next coil to be started without further attachment of the wire to the mandrel, and after a predetermined number of turns have been Wound on the new coil the wire between the finish coil and the one next started is automatically severed. Upon completion of this new coil, and movement thereof along the mandrel to the new position, the -irst coil is pushed from the mandrel and dropped into a receptacle. The machine is completely automatic in operation, the counter `re-setting after the completion of each coil, the spray gun being operative only when a coil is in the winding position, and the cutting taking place well after a new coil is started but before it is wound with the prescribed number of turns. The only operator a-ttention required is to keep the machine supplied with wire and to assist in the -starting of the coil after a new spool of wire is put on the machine.

Other objects and features of the invention, and a better understanding of its organization and operation will be had from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIG. l is a perspective View of the winding machine;

FIG. 2 is an enlarged top plan View of the right hand portion of FIG. l; and

FIG. 3 is a schematic diagram of circuitry for automatically controlling the operating sequence of the machine.

Referring now to FIGS. l and 2, the invention is illustrated as embodied on a Stevens coil winding machine of the type generally illustrated in U.S. Pat. No. 2,650,768, which comprises a housing lil in which is journaled a main shaft 12 including a chuck 14 for holding a hard polished mandrel 16. The shaft 12 is driven in rotation by a belt from an electric motor (not shown) coupled to pully 18 secured to the left end of the shaft. Shaft l2 carries a small pulley 2i?, which through a belt drive 22, drives a cycle counter 24 which controls the number of turns to be wound on the coil.

The wire 25 from which the coils are wound is supplied from a spool 26 and passes over a pulley 28, or other suitable tensioning means, :and thence through wire guide 30. Wide guide 3d is formed with a hook 30a, the bend of which lies directly over the mandrel 16 and is pivotally mounted at the other end on a rod 32. As best seen in FIG. 2, guide 3@ is held between bushings 34 and 36 and is rotatable on rod 32. A helical spring 38, secured at one end to a collar 38a, keyed to rod 32, and secured at the other end to bushing 34, urges the hook 30a downwardly upon mandrel 16 and exerts a controlled amount of pressure upon a coil as it is built up.

Rod 32 and wire guide 30 which is carried thereby, are driven back and forth by a heart-shaped earn 40, which is geared to main shaft 12, to lay the wire 25 in a predetermined pattern on the mandrel and to build up a coil, shown at 42. When a predetermined number of turns have been laid on the coil 42, as determined by the preset count in counter 24, an electrically controlled air cylinder 44, the piston rod 46 of which is attached to one end of a slide bar 48, drives the slide bar to the right in FIG. l. The other end of .the slide bar 48 is supported to slide in housing 10. Slide bar 4S carries a cam plate Sil having a cam surface Sila for lifting the Wire guide 30 away from the coil against the action of helical spring 3S, a coil stripper 52, and a stripper gate 54 hinged at 56 on an arm 58 secured to the slide bar 48. Also attached to cam plate 50, and movable therewith, is an L-shaped arm ed having a circular opening 62 therein through which mandrel 16 extends. The function of member ed, as will become more apparent when a cycle of operation is described, is to prevent the coil being wound from becoming entangled with the finished coil still on the mandrel. The travel of slide bar 43 is controlled by a switch 64 mounted -on the base of the machine and positioned to be actuated by a protuberance 65 on the slide bar. When the switch 64 is closed, the valve controlling the admission of air to cylinder 44 is reversed, and the bar 4S is driven back to its coil-winding position.

The wire extending between a iinished coil, designated 42', and the newly started coil 42 is cut with a sharpened disc 68 rotatably mounted in a bifurcated arm '70, which in turn, is pivcted at 72 on an upstanding support '74 rigidly secured to the base of the machine. At the appropriate time, disc 68 is swung up against the mandrel 16 by a solenoid '76, which when energized pulls the other end of member lil downwardly. With this night of wire rotating with the mandrel, it will be seen that engagement of the sharpened disc with the mandrel will sever the wire. When solenoid 76 is de-energized, cutter disc 63 drops away from mandrel 1.6 suliciently to allow member 6l) freely to pass the cutter.

In order that the finished coil be a rigid unit when it is stripped o. the mandrel, it is sprayed during winding, as by spray gun 78, with a material which causes successively laid down turns of wire to adhere to each other. By way of example, coils `formed of wire having cellulose acetate yarn insulation may be sprayed with acetone which `fuses the yarn on adjacent turns together. The acetone dries suiiiciently fast that the final turn on a coil is securely attached, and the turn-to-turn adhesion throughout the coil during build up results in a irm, rigid, self-supporting unit. The spray gun 78 is turned off and on, by control means to be described, in order that the acetone is sprayed only during that portion of the machine cycle when a coil is being wound.

The drawings illustrate the machine in that portion of its cycle of operation where coil 42 has just been completed, the number of turns thereon having been determined by pre-setting counter 24. When the prescribed number of turns have been applied, the cycle counter 24 stops the drive motor (not shown) and turns olf the spray gun 78. At the same time, a solenoid operated air valve 44a admits air to the left end of cylinder 44 to drive slide arm 48 to the right whereby cam arm Si) lifts wire guide 30 away from the mandrel. Also, coil stripper 52 moves the finished coil 42 along the mandrel to the position of finished coil 42', and during this movement the hinged stripper gate 54 pushes the finished coil 42 from the mandrel into a funnel Si) and a suitable receptacle (not shown).

At the extreme right end of the travel of slide bar 48, the protuberance 66 thereon engages limit switch 64 which reverses electrically operated air valve 44a to allow air to enter the right end of cylinder 44 and to drive the bar back to its original position. Closure of switch 64 `also resets counter 2d to the prescribed number, and upon resetting of the counter, a switch is actuated which starts the `drive motor and spray gun 78. With the wire now stretched from wire guide 30 to the iinished coil 42', and the mandrel being in rotation, a coil is started and the action of cam 4t) lays the wire in a spiral pattern. In other words, the completed coil 42' frictionally engaging the mandrel at the second position serves as a temporary anchor for the start lead of the new coil to eliminate the necessity of otherwise anchoring or securing the starting lead of the new coil to the mandrel. The relatively taut flight of wire between the nished coil and the -wire guide, and the wire guide urged into engagement with the mandrel by spring 38, cooperate to start a new coil on the mandrel under the wire guide. The initial turns of the new coil, laid down closely adjacent each other by the action of cam 4o, adhere to each other by reason of the application of the quick-drying adhesive from spray gun 78, producing, in effect, a form on which the remainder of the coil is wound. The application of the adhesive solution to the initial turns of the coil, and throughout the winding of the coil, insures a coil with a rm and smooth internal bore. The mandrel 16 being very smooth, such adhesive as is applied to the mandrel under the initial turns of the new coil contributes to the formation a smooth internal bore and does not result in adherence of the coil to the mandrel suicient to impede the sliding of the finished coil along the mandrel by coil stripper 52. After a few turns of the new coil have been laid down, approximately ten to twenty, determined by means to be described, solenoid 76 is energized, swinging cutter disc 68 up against mandrel i6 and cutting the connecting wire between coils 42 and 42. Solenoid 76 is energized for a predetermined time, suiiiciently long to insure that the connecting wire is cut, and upon termination of the solenoid current, the cutter 68 drops away, out of the path of travel of member 60. Again, after the preset number of turns have been wound, the yturns counter 24 stops the machine, `and the above described cycle is repeated.

FIG. 3 is a schematic diagram of a control circuit for providing the foregoing operating cycle, all switches and relay contacts being shown in the start position; i.e., just prior to the `beginning of a new coil. The circuit may be operated from a 60 cycle, llO volt system, and includes two latching relays and 92, the solenoids of which are designated 90a and 90b, and 92a and 92b, respectively, and another relay 94. With switch 96 in the position shown, having been moved to that position upon the automatic resetting of counter 24 to the preset number of turns per coil, voltage is applied to solenoid 92b of latching relay 92 and to solenoid 94. When relay 94 is energized, power is applied to the drive motor (not shown) of the winding machine, starting rotation of the mandrel. Closure of relay 94 also actuates an electrically operated valve which opens and applies air pressure to the spray gun 7 8, whereby the spraying action starts simultaneously with the start of mandrel rotation. Also, during the time that switch 96 is in the position shown, the contactors of latching relay 90 are in the position shown, having been left in that position at the conclusion of the previous cycle. Accordingly, power is applied to a motor 98, which drives a shaped cam (not shown) at a slow speed relative to the speed of rotation of the mandrel. When motor 98 starts, it initiates a time delay device 100, capable of providing a delay sufficient to allow a specified number of turns, of the order of ten to twenty, to be laid on the new coil before severing the wire between a completed coil and a new coil. At the termination of lthe delay period, time delay device 100 closes the circuit to energize the cutter solenoid '76. The motor continues to run after initiation of the time delay of device 100 through a complete revolution at which time fthe cam it drives closes switch 102 to energize solenoid 90a of the latching relay. With solenoid 90a energized, the contacts are moved to the up position, removing the power from motor 98 and de-energizing the cutter circuit.

The closure of switch 102 does not, however, stop the motor driving the mandrel, the winding continuing until the preset number of turns, controlled by the counter 24, is reached, at which-time switch 96 is moved from the position shown to the other contact. This removes power from relay 94, causing the drive motor circuit to be opened, and the spray gun 7S to be turned off. Although power is also removed from solenoid 92h, being a latching relay, the contacts remain in the position shown until` solenoid 92a is energized. When solenoid 92 is energized, power is applied to the solenoid actuated valve 44a on cylinder 44, to drive slide bar 48 to the right (FIG. l), limit switch 64 being closed when the bar reaches the right extremity of travel. Closure of switch 64 applies power to solenoid 92a of latching relay 92 to reverse the position of the contacts, thereby removing energizing power from the air valve This valve is so arranged that upon de-energization of the solenoid, air is admitted at the right end of the piston to drive it back to its original position. Closure of switch 64 also applies power to solenoid 90b of latching relay 96 to return the contacts to the position shown to ready the cutter activating circuit for the next cycle. Power is also applied to the solenoid 24a associated with counter 24 which resets the turns counter 24 by a linkage mechanism 24h (partially shown in FiG. l) to the predetermined number. As counter 24 is being reset, switch 96 is moved back to the position shown in FIG. 3, and the machine is ready for the next cycle.

Brieiiy reviewing the operation of the machine, following removal of the finished coil 4Z to the position shown in FIG. l, the wire guide 3o carried by slide bar 458 continues to engage the wire and starts the winding of a new coil 42 at the position shown. Concurrently with the start of a new coil, spray gun 78 is opened to spray the coil th-roughout the winding thereof, and upon completion of the coil, as determined by the counter 24, the drive motor and spray gun are cut off, and the coil 42 urged to the position of coil 42', pushing coil 42' from the mandrel. Upon return of the slide bar to its initial position, the counter is reset, the wire is drawn back to the position illustrated, and the machine is ready for the next cycle.

It will be apparent from the foregoing that the machine is completely automatic in operation, operator attention being required only to supply the machine with wire and the spray solution. The machine has been found to vsatisfactorily wind coils with a minimum variation in electrical characteristics at a rate of about 50() coils per hour for formless coils having 200 turns. It will be understood that the machine is capable of winding formless coils having any desired number of turns by adjusting the setting of counter 24, and the length of the coil may be varied by changing heart-shaped cam dit.

While a speciiic embodiment of the invention has been described, a number of variations within the scope of the invention will now be suggested to those skilled in the art. For example, although an acetone spray for cellulose acetate yarn insulation has been suggested and is eminently satisfactory, it will, of course, be necessaryto use some other spray solution on wire having a different insulation. For example, a wire insulated with cotton yarn might be sprayed with a quick drying shellac or varnish, another insulation may require still another solution, Kthe objective in each case being to cause adherence of adjacent turns of the wire during the winding operation. The control circuit for actuating the cutter after a few turns of a new coil have been wound may also take a variety of forms, the one described having been found to be very reliable and inexpensive. Likewise, means other than an air cylinder i4 might be found more satisfactory for actuating slide bar (ifi. Accordingly, it is applicants intention that the scope of his invention be limited only by the appended claims.

What is claimed is:

i. Apparatus for winding formless coils comprising a rotatable smooth cylindrical mandrel, means including a reciprocating guide for laying a strand in a predetermined pattern at a first position on said mandrel, means for spraying said strand at said lfirst position with a material to cause adjacent turns to adhere to each other, and means operable upon completion of a coil at said first position to stop rotation of said mandrel and reciprocation of said guide and to slide the completed coil to a second position on said mandrel while maintaining the finish lead of the completed coil in engagement with said guide, the completed coil at said second position frictionaily engaging said mandrel with the finish lead thereof cooperating with said guide to start the winding of a new coil at said iirst position.

2. Apparatus for winding formless coils comprising a rotatable smooth cylindrical mandrel, means for driving said mandrel in rotation, means including a guide reciprocably driven by said driving means in a direction parallel to said mandrel for laying a strand in a predetermined pattern at a first position on said mandrel, means for spraying the strand at said rst position with a materiai to cause adjacent turns to adhere to each other,

ieans operable upon completion of a coil at said first position to stop said driving means and to slide the completed coil to a second position on said mandrel While maintaining the finish lead of the completed coil in engagement with said guide, the completed coil at said second position frictionally engaging said mandrel with the finish lead thereof cooperating with said guide to start the winding of a new coil at said first position, and means operative during the sliding movement of a completed coil from said iirst position to said second position to remove 6 a completed coil in said second position from the mandrel.

3. Apparatus for winding formless coils comprising a rotatable smooth cylindrical mandrel, means for driving said mandrel in rotation, a wire guide driven by said driving means and arranged for reciprocating motion in a direction parallel to said mandrel for laying a wire in a predetermined pattern at a rst position on the mandrel, means for spraying a coil being wound at said first position with a material to cause adjacent turns to adhere to each other, means operable upon completion at said rst position of a coil having a predetermined number of turns to stop said driving means and to slide the completed coil to a second position on said mandrel while maintaining the finish lead of the completed coil in engagement with said wire guide, the completed coil at said second position rictionally engaging said mandrel with the finish lead thereof cooperating with said Wire guide to start a new coil at said first position, means for severing the strand between the completed coil at said second position and the wire guide after a predetermined number of turns have been wound on said new coil, and means operative during sliding movement of a completed coil from said first position to said second position for removing a completed coil in said second position from the mandrel.

4. Apparatus for winding formless coils comprising a rotatable smooth cylindrical mandrel, means for driving said mandrel in rotation, a wire guide driven by said driving means and arranged for reciprocating motion in a direction parallel to said mandrel for laying a wire in a predetermined pattern at a rst position on the mandrel, means operable upon completion of a coil at said first position to stop said driving means and to slide the completed coil to a second position on said mandrel white maintaining the nish lead of the completed coil in engagement with said Wire guide, the completed coil at said second position frictionaliy engaging said mandrel with the finish lead thereof cooperating with said wire guide to'start a new coil at said first position, means operative only during rotation of said mandrel for continuously spraying a coil being wound at said first position with a material to cause adjacent turns to adhere to each other, means for severing the strand extending from said wire guide to a completed coil at said second position after a predetermined number of turns have been wound on said new coil, and means operative during sliding movement of a completed coil from said iirst po sition to said second position for removing a completed coil in said second position from the mandrel.

5. Apparatus for winding formless coils comprising, a rotatable smooth cylindrical mandrel, means for driving said mandrel in rotation, means including a wire guide arranged for reciprocating movement in the direction of the axis ot said mandrel for winding a strand in a predetermined pattern at a first position on said mandrel, means for spraying a coil being wound at said iirst position with a material to cause adjacent turns to adhere to each other, counter means operative by rotation of said mandrel for controlling the number of turns wound on a coil, means controlled by said counter means and arranged to slide a completed coil to a second position on said mandrel while maintaining the finish lead of the completed coil in engagement with said wire guide, the completed coil at said second position rictionally engaging said mandrel with the finish lead thereof cooperating with said Wire guide to start the winding of a new coil at said first position, means for severing the strand extending between a completed coil at said second position and a newly started coil after a predetermined number of turns have been Wound on the newly started coil, and means operative during sliding movement of a completed coil from said first position to said second position for removing a completed coil in said second position from the mandrel.

6. Apparatus for automatically winding formless coils comprising a rotatable smooth cylindrical mandrel, means for driving said mandrel in rotation, means including a wire guide mechanically coupled to said driving means and arranged for reciprocating movement adiacent said mandrel for winding a strand in a predetermined pattern at a first position on said mandrel, means for spraying a coil being wound at said first position with a material to cause adjacent turns to adhere to each other, means including an automatically pre-settable counter operable upon completion at said rst position of a coil having a predetermined number of turns to stop said driving means and to slide the completed coil to a second position on said mandrel, said wire guide, upon movement o` a completed coil to said second position, remaining in said first position with the strand from the final turn of the completed coil drawn therethrough, said last-mentioned means further including means for resetting said counter and starting said driving means to start a new coil, the completed coil at said second position frictionally engaging said mandrel with the strand from the final turn thereof cooperating with said wire guide to start a new coil at said lirst position, and cutter means cooperatively arranged with said mandrel for severing the strand between the completed coil at said second position and the wire guide after a predetermined number of turns have been wound on the newly started coil.

7. Apparatus for automatically winding formless coils comprising a rotatable smooth cylindrical mandrel upon which a strand is wound, means for driving said mandrel in rotation, means including a wire guide mechanically coupled to said driving means and arranged for reciprocating movement adjacent said mandrel for winding the strand in a predetermined pattern at a first position on said mandrel, means including an automatically pre-settable counter operable upon completion at said first position of a coil having a predetermined number of turns to stop said driving means and to slide the completed coil to a second position on said mandrel with the strand from the final turn of the completed coil drawn through said wire guide, the completed coil at said second pos rictionally engaging said mandrel with the strand from the final turn thereof cooperating with said wire guide and said rotatable mandrel to start a new coil at said first position, means operative in response to the movement of a finished coil to said second position to reset said counter and to re-start said driving means, means operative only during rotation of said mandrel for continuously spraing a coil being wound at said first position with a material to cause adjacent turns to adhere to each other, cutter means arranged to engage said mandrel and operative upon the winding of a predetermined number of turns on a newly started coil to sever the strand between the cornpleted coil at said second position and said wire guide, and means operative during sliding movement of a completed coil along said mandrel from said first position to said second position for removing a completed coil in said second position from the mandrel.

S. A method of winding torrniess coils on a coil winding machine having a rotatable smooth cylindrical mandrei and a wire guide, comprising the steps of: winding a coil having a predetermined number of turns at a first position on the mandrel while spraying the coil with a material to cause adjacent turns to adhere to each other, stopping rotation of the mandrel and sliding the completed coil to a second position on the mandrel with the strand trom the final turn of the completed coil drawn through the wire guide, the completed coil at said second position :t'rictionally engaging said mandrel with the strand from the final turn thereof cooperating with the wire guide und rotation of said mandrel to start a new Coil at said first position upon re-starting of the rotation of the mandrel, re-starting the rotation of said mandrel, and severing the strand between the completed coil at the second position and the wire guide after a predetermined number of turns have been wound on the newly started coil.

9. A method of winding form ess coils on a coil winding machine including a rotatable smooth cylindrical mandrel supported at one end an a wire guide cooperating with the mandrel, comprising the steps of: winding on the mandrel under the guide a coil having a selected number of turns while spraying the coil with a material to cause adjacent turns to adhere to each other, stopping the mandrel and sliding the completed coil to a second position on the mandrel near the unsupported end thereof with the strand of the final turn of the completed coil drawn through the wire guide, restarting the mandrel to start a new coil under the wire guide, the completed coil at said second position frictionally engaging said manrel with the strand of the final turn thereof cooperating with the wire guide and the rotating mandrel to start the new coil, and cutting the strand between the completed coil at the second position and the wire guide after a predetermined numbcr of turns have been wound on a newly started coil.

l0. A method of winding formless coils on a coil winding machine including a rotatable smooth cylindrical mandrel supported at one end and a wire guide cooperating with the mandrel, comprising the steps of: winding on the mandrel under the guide a coil having a selected number of turns while spraying with a material to cause adjacent turns to adhere to each other, stopping the mandrel and sliding the completed coil to a second position on the mandrel near the unsupported end thereof with the strand of the final turn of the completed coil drawn through the wire guide, re-starting the mandrel to start a new coil under the wire guide, cutting the strand between the completed coil at the second position and the wire guide after a predetermined number of turns have been wound on a newly started coil, and sliding the completed coil at said second position from the unsupported end of the mandrel during movement of the next completed coil to said second position.

ll. A method of winding formless, self-supporting coils on a coil winding machine having a rotatable smooth cylindrical mandrel supported at one end and a wire guide cooperating with the mandrel, comprising the steps of: winding a selected number of turns of wire having cellulose acetate yarn insulation on the mandrel under the guide while spraying the wire with acetone, stopping the mandrel and sliding the completed coil to a second position on the mandrel near the unsupported end thereof with the strand of the final turn of the completed coil drawn through the wire guide, re-starting the mandrel to start a new coil under the wire guide, and cutting the strand between the completed coil at said second position and the wire guide after a predetermined number of turns have been wound on the newly started coil.

l2. A method of Winding formless, self-supporting coils on a coil winding machine having a rotatable smooth cylindrical mandrel supported at one end and a wire guide cooperating with the mandrel, comprising the steps of: winding a selected number of turns of wire having cellulose acetate yarn insulation on the mandrel under the guide while spraying the wire with acetone, stopping the mandrel and sliding the completed coil to a second position on the mandrel near the unsupported end thereof with the strand of the final turn of the completed coil drawn through the wire guide, re-starting the mandrel to start a new coil under the wire guide, cutting the strand between the completed coil at said second position and the wire guide after a predetermined number of turns have been wound on the newly started coil, and sliding a completed coil at said second position from the unsupported end of the mandrel during movement of the next completed coil to said second position.

13. Apparatus for automatically winding formless coils comprising, in combination, a rotatable smooth cylindrical mandrel, means for driving said mandrel in r0- tation, means including a reciprocating guide driven by said driving means for laying a strand in a predetermined pattern to form a coil at a first position on said mandrel, means for continuously spraying said coil throughout the period of Winding thereof with a quickdrying adhesive to cause adjacent turns of the coil to adhere to eachother while being Wound, and means operable upon completion of a coil at said first position to stop said driving means and to slide the completed coil to a second position on said mandrel while maintaining the Ifinish lead of the completed coil in engagement with said guide, the said completed coil frictionally engaging said mandrel at said second position with the nish lead thereof cooperating with said guide and said' mandrel to start the winding of a new coil at said rst position upon re-starting said driving means.

References Cited in the le of this patent UNITED STATES PATENTS 1,995,916 Coll-ins Mar. 26, 1935 2,122,468 Hill July 5, 1938 2,445,109 Ferguson July 13, 1948 2,527,662 Stevens Oct. 31, 1950 2,595,791 Hunt May 6, 1952 2,631,788 Cer-asani Mar. 17, 1953 2,848,794 Roth Aug. 26, 1958 

